1. Field of the Invention
The present invention relates to a filter assembly for collecting material that is entrained in a fluid stream, and to a filter element for use in the assembly.
2. Description of Related Art Including Information Disclosed Under 37 CFR 1.97 and 37 CFR 1.98
A conventional filter assembly, e.g. for removing liquid droplets from compressed air, has a housing which contains a consumable filter element located in the flow path of a fluid to be filtered so that the fluid flows through the element.
A typical filter assembly includes a housing manifold which is detachably joined to a housing bowl, the filter element having a first end cap which engages with the manifold. The filter element is usually tubular in shape and can be removably inserted into the manifold when the bowl is detached from the manifold. The bottom of the filter element typically terminates in a second end cap.
Fluid to be filtered is directed from an inlet port in the manifold via an opening in the first end cap to the central region of the filter element, the fluid then flowing through the filter material of the filter element and exiting the assembly through an outlet port, typically in the manifold.
The first end cap typically has a formation which sealingly engages with a corresponding formation on the manifold to prevent leakage of fluid en route from the inlet port to the central region of the filter element. As illustrated for example in GB 2222536A, the top end cap can have a spigot in which the opening in the end cap is formed, the spigot inserting into a receiving port of the manifold and the seal being effected by O-rings.
WO 1999/030798 proposes a different arrangement, in which a filter assembly includes a housing for a tubular filter element, the housing having a manifold providing inlet and outlet ports for the gas that is to be filtered. Instead of a simple spigot, the filter element has at one end a flow conduit which has a first conduit opening communicating with one of the ports and a second conduit communicating with the central region of the filter element, the flow conduit curving through about 90° between the first and second conduit openings. To form a seal between the first conduit opening and the respective manifold port, the flow conduit has to be slid transversely relative to the direction of flow of fluid through the port. Wedge formations force mating surfaces of the first conduit opening and the manifold port together during the transverse sliding to enhance the seal.